Register a LINUX_EFI_INITRD_MEDIA_GUID DevicePath with a LoadFile2Protocol interface and serve the initrd to a supported Linux kernel (Version 5.8+) Leave the x86 code for older kernels in place until supported kernels become more mainstream
This adds assembly to read the platform timer from the CP15 coprocessor register `cntpct_el0` and the frequency from `cntfrq_el0`